Various systems and methods have been proposed for tracking vehicles on a highway system in a metropolitan area. Such systems and techniques typically rely on vehicles that are equipped with a location-determining unit such as, for example, GPS (global positioning system) receivers to determine a location of a given vehicle at any given time, or sensors actively monitoring the position of vehicles on the highway system. The position information for the vehicles may be transmitted to a central tracking station which keeps track of the vehicles on the highway system. Inertial navigation systems and methods have also been employed to maintain the position information of vehicles with respect to a highway system as the vehicles move along the highway system. Such systems and methods can be expensive and complex, often requiring the position-determining devices to be on each vehicle to be tracked, and often requiring expensive and complex sensors to be positioned at intervals along the highway system.
Published U.S. patent application 2005/0071079 A1 describes a method and apparatus for improving vehicle tracking and remote control. A wireless telecommunications system infrastructure receives a unique vehicle identifier via a shared-communications channel from a vehicle being tracked, as well as location information for that vehicle. The location information is derived from Global Positioning System signals or from the address of the local infrastructure currently in contact with the vehicle, or both. The same shared-communications channel is used to convey control messages to the vehicle, wherein the messages are mapped into control signals that can disable the vehicle's engine or control some other system that is part of the vehicle.
U.S. Pat. No. 5,617,086 describes a traffic monitoring system comprising a set of in-road sensor arrays for providing signals in response to a vehicle traversing the sensor arrays, a processor unit for processing the signals to determine vehicle speed and specific parameters such as axle count and spacing, and a traffic signal or sign controllable by the processor unit.
U.S. Pat. No. 6,345,228 B1 describes a road vehicle sensor that provides an output signal having a magnitude which varies with time through a plurality of values as a vehicle passes the sensor. Signal processing apparatus monitors the timing of sensor signals generated from sensors in adjacent lanes of a highway and provides an indication when such sensor signals could correspond to a double count with a single vehicle being detected by both sensors.
U.S. Pat. No. 4,633,407 describes a method and a device for target tracking of land vehicles for use in heavily meshed city road systems. A motor vehicle device is used with an input device for a desired target location and an output device for vehicle instructions. The vehicle location (determination of travel path and travel location) is carried out by picking up and evaluating the wheel rotations of a non-driven vehicle axis.
U.S. Pat. No. 5,878,367 describes monitoring traffic in individual lanes of a roadway as to vehicle count or presence, speed and direction of movement by mounting a microphone array high above the road surface, digitizing the output signals of the microphones, filtering, beamforming and storing the digitized signals to provide separate power histories for separate locations in individual lanes. These power histories are then analyzed to provide vehicle movement data for each lane.
Published U.S. Patent Application 2005/0088320 A1 describes a system for registering and tracking vehicles. The system comprises an RFID tag affixed to a vehicle and a scanner, wherein the scanner is adapted to query the RFID tag when proximate the RFID tag, effective to obtain information relating to at least one of the vehicle and an owner of the vehicle.
U.S. Pat. No. 6,853,910 B1 describes a method of tracking vehicles comprising monitoring for registration request signal data and receiving the registration request signal data at a call center.
U.S. Pat. No. 6,833,811 B2 describes a method and system for tracking an object by generating GPS coordinates for the object and a bearing associated with a movement of the object.
U.S. Pat. No. 6,737,989 describes a tracking unit for a vehicle that may include a vehicle position determining device, a wireless communications device, and a controller cooperating with the wireless communications device and the vehicle position determining device to determine and send vehicle position information to a monitoring station.
Further limitations and disadvantages of conventional, traditional, and proposed approaches will become apparent to one of skill in the art, through comparison of such systems and methods with the present invention as set forth in the remainder of the present application with reference to the drawings.